302 



Irrigation and Drainage 



est type of collecting and distributing systems yet devised, and 

 it is one which meets the peculiar demands brought upon it with 

 almost ideal nicety. From the collecting reservoir, up in the 

 mountains, behind the great Bear valley dam, the water travels 



Fig. 63. Cement hydrant, with water discharging outward 

 into distributing flume. 



hurriedly much of the way through closed pipes of redwood, 

 steel or cement, in which all evaporation and seepage are effec- 

 tually prevented, while for most of the balance of the distance 

 the water glides swiftly along tight flumes and cement-lined 



Fig. 64. Same hydrant as Fig. 63, with water discharging 

 over left wier into underground pipe. 



canals of nearly faultless alignment, reaching its destination with 

 so little of erosion or silting that the annual expense for mainte- 

 nance is almost a trifling matter. The dangers from alkalies are 

 reduced to the narrowest possible margin, and the swamping of 



